Iíve been researching the internet for days and Iím trying to figure out which cartridge (5.56X45mm / 7.62X39mm) is more effective on a soft-tissue at a range of within 50 yards. The scenario is that the 5.56 is fired out of a 14.5Ē barrel and 7.62 is fired out of a 16Ē barrel. I understand the 5.56 can reliably fragment at 2700 ft/sec, but out of a 14.5Ē barrel, itís barely going to achieve that, also if you factor in clothes, the bullet velocity will be slower when it hits soft tissue. Iíve looked for ballistic gel reports on these two rounds, but found very little on the 7.62. Iíve looked into the new standard Russian round the 5.45X39mm (down from the 7.62), and wondered if they made a good choice. They downgraded since the 5.45 will yaw sooner, but doesnít have data if the 5.45 also fragments well enough to stop an angry man. I mean, Iíve read/heard many stories about US soldiers complaining about the 5.56 and itís stopping power. Yet, I havenít heard/read of anyone complaining about the 7.62 and itís stopping power (in close range). Iím also interested in the cartridges available for both these calibers. The best cartridge that I found in the US for the 5.56 is the Hornadyís Tap Ammo (75gr). For the 7.62, donít know which is good and Iím looking for peopleís suggestions. Also any data, ballistic gel pictures of these calibers. I would like to keep this thread on just these 2 calibers and not mention the 7.62X51mm or .308Öetc.

swhatb

03-14-2007, 11:08 PM

6.8 SPC Round :D

whatever

03-14-2007, 11:19 PM

Ugh....

If you have been researching for days why haven't you found the Ammo Oracle?

Cali-V

03-14-2007, 11:21 PM

AR15.com Ammo Oracle (http://www.ammo-oracle.com/body.htm)

Adog5

03-15-2007, 1:56 AM

Ugh....

If you have been researching for days why haven't you found the Ammo Oracle?

I've read the Ammo Oracle already and the only thing they say about the 7.62X39mm is the following (everywhere else talks about the 7.62X51mm):
"Data on hundreds of shootings collected by the Army Wound Data and Munitions Effectiveness Team and data from civilian shootings with 7.62◊39mm ammunition, like from the AK-47, bear out the less than stellar lethality of the round."

That is the ONLY thing that is mentioned about the 7.62X39mm. If you read my intital posting, I'm specifically looking for more data about the 7.62X39mm. The Ammo Oracle doesn't provide it.

So let me ask why reports from Iraq are talking about the ineffectiveness of the 5.56 (M193) in close range combat? Isn't that why some special foreces were using the 6.8 SPC? Isn't the whole point of Barrett going to the 6.8 SPC for better stopping power at close range? The 6.8 SPC obviously isn't for long range shooting (The 5.56 is better for that).

Even with the quote above, they said they collected hundreds of Wound Data, can you show me a link to a site that has this? I'm starting to think that the AR-15 round is not as good as the AK-47 within 50 yards.

wutzu

03-15-2007, 2:15 AM

If you're looking for the best round to kill zombies, JBTs, home invaders, space invaders, etc., go with the hardest hitting round you can shoot accurately.

If this is a purely academic exercise, know that the Mk 262 5.56 ammo seems to be fragmenting quite nicely at close range out of 14.5" barrels. it also hits harder at longer ranges. Most importantly, it's cheaper than that TAP stuff, which is overpriced varmint ammo.

Pryde

03-15-2007, 2:26 AM

I don't buy the ammo oracle because it was compiled by arfcom associates who I believe may be out to show that the 5.56 isn't as bad as people want you to think.

The 7.62x39 is far superior to the 5.56 in transferring energy from the projectile to the victim. If you shoot a metal bucket with 5.56, the round will go straight through both sides, if you shoot the same bucket with a 7.62x39 you will make it jump and dance all over the place. (Feel free to test this yourself)

IIRC on an episode of futureweapons where they were testing the barrett 6.8 rifle, they did this test on steel silhouette targets. The 5.56 passed straight through the targets and the 7.62x39 and the 6.8 would knock them down.

As far as accuracy is concerned, the 5.56 wins by a large margin, the 7.62x39 just isn't a very accurate round.

Prc329

03-15-2007, 8:09 AM

IIRC on an episode of futureweapons where they were testing the barrett 6.8 rifle, they did this test on steel silhouette targets. The 5.56 passed straight through the targets and the 7.62x39 and the 6.8 would knock them down.

As far as accuracy is concerned, the 5.56 wins by a large margin, the 7.62x39 just isn't a very accurate round.

I just watched that on my DVR. The 5.56 hit the steel every time in almost the same place but did not knock it over. The 7.62 it and knocked it over but was very inconsistent at hitting the target. The 6.8 hit it and knocked it down every time.

luvtolean

03-15-2007, 8:22 AM

It seems to me, if I was in a combat situation, I'd want a round that penetrated things like steel so I could shoot through an enemy's suspected cover. I know for a fact 7.62x51 will punch cleanly through more steel than 5.56, as I have personally tried it. Does that make it a bad round?

The 5.56 has to have time, and enough velocity at impact, to go through the yaw cycle, break apart, and take the person out of the fight.

It was designed to punch through steel.

I know people that have shot others with 5.56, and when I mentioned online rambos debate one of my friend's comments was, "I don't want to get shot with it; yes, it works."

Of course, there are people I've talked to in the service, especially Vietnam era guys, who don't, and will never like the 5.56 too.

Adog5

03-15-2007, 8:31 AM

It seems to me, if I was in a combat situation, I'd want a round that penetrated things like steel so I could shoot through an enemy's suspected cover. I know for a fact 7.62x51 will punch cleanly through more steel than 5.56, as I have personally tried it. Does that make it a bad round?

How about the 7.62X39mm? That is the round I'm most interested in. Also, in my scenario, it's most likely just the clothes that would be the obstruction and maybe some glass. If you had to pick between the AR15 or the AK47, which would it be and why?

luvtolean

03-15-2007, 8:36 AM

Honestly, I can only regurgitate what I've read. I've never been in combat, and I've never shot people with either.

But the 7.62 does not go through a yaw cycle, and typically does not fragment.

I've never tried hard target penetration testing with it either to compare. But neither are going to be very good against glass.

Go look for ballistic gelatin testing with the two, and make judgements based on that.

You have to also compare the platforms that launch the bullet, and I personally prefer the AR15 by a large margin, though I do enjoy low dollar plinking with my 7.62x39 carbine.

In court, I'd also much rather the prosecutor be holding up "our" weapon rather than a "the terrorist weapon".

twl

03-15-2007, 9:57 AM

Just saying "5.56" is too broad of a category.

You need to define the bullet being used.

The M193(55gr) bullet will do quite fine at the close ranges you mention, out of a 14.5" barrelled M4. It will greatly exceed the terminal effects of a 7.62x39 round at the same distance, due to early yaw and fragmenting effects.
The M855(62gr) is often less effective, because its starting velocity is lower, and it also has the steel penetrator inside, which inhibits the fragmentation. It is marginal at 50yds, when shot from a 14.5" M4 barrel.
The Mk262(77gr) is highly lethal at way beyond 50yds from a 14.5" barrel.
It will be way better than any 7.62x39 round for CQB.

6.8SPC is better than any of them, at even longer ranges.

Essentially, the crux is this: if the 5.56 round is within normal fragmentation range(necessary velocity at the given distance), it will outperform any 7.62x39 round because of the terminal effects of the projectile. If the velocity of the 5.56 round is lower than necessary fragmentation velocity, then it will make a smaller hole than a 7.62x39, and may be less effective because of that, IF the shot placement is close enough for the .30 cal round to touch a vital organ that the .22 cal projectile would miss.

Since the 5.56 from an AR15 platform will generally produce a better accuracy level which should produce better shot-placement, AND also produce a larger wound cavity(when within fragmentation range), it has a much higher probability of lethality in CQB than an AK with 7.62x39.

The 7.62x39 should have better barrier-penetration abilities, because of the non-fragmenting nature of the projectile, and it's heavier mass to carry it thru.

However, I wouldn't want to get shot with either of them at any distance.

1911su16b870

03-15-2007, 10:12 AM

...You need to define the bullet being used...

However, I wouldn't want to get shot with either of them at any distance.

+1

Rifle cartridges have 4 to 10 times the energy of handgun rounds. A solid hit in the thorasic triangle with either should effect stoppage. Fortunately I have not had to personally verify this hypothosis. :)

jaymz

03-15-2007, 10:12 AM

Coke or Pepsi?

It doesn't really matter which round you use. Either one will kill a man dead at combat range. If I were shooting looong distance, I wouldn't be using an AR or an AK. I would be using a scoped .308, or for reallllly looong distance, .50 BMG. Just my two one hundredths of a dollar. :)

Paratus et Vigilans

03-15-2007, 10:13 AM

Isn't this one of those questions that has no absolute answer?

It's going to come down to personal preference.

Each platform, and each round, excels or fails to excel depending on the variables in any given permutation.

At a longer distance, you've got a better chance of hitting the subject with the AR and a 5.56 round because of its inherently greater accuracy. So, even if you've got a better chance of a one hit takedown with the AK and a 7.62 round - the big IF there is whether you can get a hit on the subject at the longer distance, which is a lower probability with the AK and a 7.62 round, if everything else in the equation is equal.

At really close range, you're going to mess them up bad with a AK and a 7.62 round, and hitting the subject will be far less of an issue at short range.

Then you have to get into the whole question of whether "stopping power" means energy transfer or tissue damage to the subject. The 7.62 is going to put a good size hole in your subject, front and rear. The 5.56 is going to make a smaller hole and chew them up inside pretty badly. What's going to "stop" the subject sooner, and more fully? Well, hopefully you're not trying to take down Rasputin, who seemed to demonstrate a remarkable resiliency. The point is, that the answer is likely unknowble, and has a whole lot more do to with who you're shooting, what they're wearing, what tissue and organs you perforate with your shot, and what kind of constitution the subject possesses, than it does with the round you're using.

On the other hand, if you're talking about shooting someone who has intruded into your home, a load of 12 GA 00 will provide all the "stopping power" you need, and then some. You will then have to call a coroner, a house painter and a carpet layer to take care of what's left. You may want to call a realtor, too, since the on-demand video replay in your brain might be a bit much to handle on a daily basis.

Mute

03-15-2007, 10:14 AM

The complaints of the ineffectiveness of the 5.56 round has mainly been from the SF teams which mostly use shorter barrel (less than 16") carbines. That is also why the 6.8 SPC has mostly seen usage by the same groups and not in general deployment.

Fjold

03-15-2007, 10:29 AM

The problem is that we expect one round to do everything, in every situation.

The issues are:

1.) The projectile will not accurately engage targets at 600 yards with a surety of lethality.
2.) The projectile will not defeat lightly armored targets and still upset in soft tissue enough to instantly incapacitate the target.
3.) The projectile does not transfer enough energy in close range soft targets sufficiently to instantaneously incapacitate them.
4.) The round must be able to be to be used effectively by the most minimally trained, least recoil tolerant solider in the field.

I don't think that there is any cartridge made that will meet the current rules of civilized warfare, treaties, etc. that will meet all of those criteria.

GlockComa

03-15-2007, 10:45 AM

Didn't National Georgraphic or Discovery do a show about Firearms projectiles and ballistics test. I think I recorded it and will have to find the dvd some where.

I should what each round fired from different handguns and rifles would do to a humans body (Ballistics gels).

I think it showed that the 7.62x39 round does alot of damage cause as soon as the projectile enters the body it tumbles causing alot of internal damage.

The 5.56 is showed going in at such velocity that it made a big entry wound and also fragmented causing internal damages as well.

Sorry if I'm wrong but I'll try to find the DVD I burned some where.

Aluisious

03-15-2007, 11:16 AM

Just keep shooting until they drop.

Both rounds will kill someone in their slightly different ways. Neither is magical or will make up for your accuracy.

IMO, since you were asking about home defense earlier, 00 buck is definately more effective than either rifle round mentioned. Why make one hole when you can make 9 or 12?

Parting shot...I tend to favor the bigger, heavier bullet. You can propel a grain of sand to an awesome kinetic energy level at tens of thousands of miles per hour but it's not going to do much damage to a person. A spear thrown by a person, on the other hand, will quickly take someone right out of a fight.

bwiese

03-15-2007, 11:33 AM

IMO, since you were asking about home defense earlier, 00 buck is definately more effective than either rifle round mentioned. Why make one hole when you can make 9 or 12?

Many many folks shot by #00 buck live long enough to be a threat - even if they're dead 2 min later. The goal of shooting someone is generally to stop an immediate threat.

#00 buck is about identical in diameter as a 32ACP bullet, which is a 'mousegun' round. Such shotgun rounds top out at 1200fps muzzle velocity and many loads are 'reduced recoil' (i.e, lighter loading = lower speed). MV drops precipitously at short ranges with this. So actually a 223 rifle w/good ammo would have higher lethality.

M1A Rifleman

03-15-2007, 11:41 AM

Look at the energy for each round, say at 100 or 200 yds. The 7.62 x 39 will be close to a 30-30, and will have more energy than the 223. The 223 has higher velocity, will be flatter in trajectory, will be more accuate, but will not have the energy = knock down power at distances when compared with the 7.62.

Geoffkoop

03-15-2007, 11:44 AM

I would personally go with a grenade:)

Incitatus

03-15-2007, 11:51 AM

I would personally go with a grenade:)

Me, with a 45-70 Govt.

DIG

03-15-2007, 12:01 PM

Iíve been researching the internet for days and Iím trying to figure out which cartridge (5.56X45mm / 7.62X39mm) is more effective on a soft-tissue at a range of within 50 yards. ...Also any data, ballistic gel pictures of these calibers. I would like to keep this thread on just these 2 calibers and not mention the 7.62X51mm or .308Öetc.

Keep it simple. Within 50yds as mentioned above, I'd personally go with a well-placed shot from the heavier projectile. For home defense 12gu 00buck should be enough, even if the first rd doesn't KILL him, you have plenty of time to follow up with another shot.

xenophobe

03-15-2007, 12:02 PM

IMO, since you were asking about home defense earlier, 00 buck is definately more effective than either rifle round mentioned. Why make one hole when you can make 9 or 12?

Unless you're talking about a tactical load 00 buck, standard velocity 00 buck is too powerful for 'home defense'. A low base birding round is much more effective and damaging to someone at close range, and won't have the momentum to travel through multiple walls... So unless you're living out in the outback without anybody around, 00 buck is your last defensive choice, IMO.

Aluisious

03-15-2007, 12:06 PM

Many many folks shot by #00 buck live long enough to be a threat - even if they're dead 2 min later. The goal of shooting someone is generally to stop an immediate threat.

#00 buck is about identical in diameter as a 32ACP bullet, which is a 'mousegun' round. Such shotgun rounds top out at 1200fps muzzle velocity and many loads are 'reduced recoil' (i.e, lighter loading = lower speed). MV drops precipitously at short ranges with this. So actually a 223 rifle w/good ammo would have higher lethality.

Projectile speed doesn't doesn't magically cause wounds by itself. 9 little .32 caliber holes have nine chances to hit "the good stuff" that ends a fight. A .223 with all it's speed doesn't mean dink if it doesn't hit a vital organ.

The hope is a .223 will fragment and destroy a large volume of tissue, but 00 buck will do the same without fragmentation anyway.

Aluisious

03-15-2007, 12:09 PM

Unless you're talking about a tactical load 00 buck, standard velocity 00 buck is too powerful for 'home defense'. A low base birding round is much more effective and damaging to someone at close range, and won't have the momentum to travel through multiple walls... So unless you're living out in the outback without anybody around, 00 buck is your last defensive choice, IMO.
Bird rounds have questionable penetration capabilities. If some big guy is wearing a tough jacket and you have to shoot through his arm to get to his torso, is a bird load going to get through all that?

Overpenetration? Eh. There are so many walls and fences and other obstructions between my neighbors and I that I'd have to be tremendously unlucky to hit anyone accidentally. I don't judge that to be a major risk, compared to the risk that birdshot won't get the job done.

Aluisious

03-15-2007, 12:14 PM

Look at the energy for each round, say at 100 or 200 yds. The 7.62 x 39 will be close to a 30-30, and will have more energy than the 223. The 223 has higher velocity, will be flatter in trajectory, will be more accuate, but will not have the energy = knock down power at distances when compared with the 7.62.

I want to know how kinetic energy has much to do with "knockdown power."

The physical force applied by a bullet that would knock someone over would be momentum, and bullet momentum is really quite pathetic.

If you're talking about terminal effectiveness, that's more a function of bullet design than raw energy. FYI, much of the kinetic energy of a projectile will turn into heat. So you'll make his wound warm...:p

M1A Rifleman

03-15-2007, 12:25 PM

I want to know how kinetic energy has much to do with "knockdown power."

The physical force applied by a bullet that would knock someone over would be momentum, and bullet momentum is really quite pathetic.

If you're talking about terminal effectiveness, that's more a function of bullet design than raw energy. FYI, much of the kinetic energy of a projectile will turn into heat. So you'll make his wound warm...:p

I think you sre mixing up another subject called bullet design rather than the actual effectiveness or energy of a caliber. Bullet design does have a factor in how it responds or how much energy the bullet transmits to the target. A poor bullet design will lose energy in the form of heat due to resistance or will tend to not transmit as much energy upon impact (SP vs FMJ).

In testing two different calibers, generally the idea would be to use the same type of bullet (FMJ, SP, HP, etc) and a standard ditance from muzzel to target.

Aluisious

03-15-2007, 12:29 PM

BTW by "design" I also mean mass, size, etc, not just whatever fancy shape or materials are used.

Point is the physical characteristics of the bullet are primary in it's wounding effectiveness. As a rule of thumb more bullet = more wound, more reliably in more situations.

ALL bullets transmit energy to a target through heat in similar manners. There's no magical method of transferring energy other than that. A good bullet will use some energy to deform itself into a nice large cross section so as to contact more tissue but that's about it. The momentum (which is the only thing other than heat "transferred to a target" of a bullet) is not changed by bullet design in terms of shape etc at all.

In the end it all still boils down to making a hole in something important, and a big heavy bullet is the tried and true method of doing that.

.223s were selected for being light and easy to carry, and for making weapons smaller and lighter, not for magical properties of high velocity projectiles.

M1A Rifleman

03-15-2007, 12:33 PM

BTW by "design" I also mean mass, size, etc, not just whatever fancy shape or materials are used.

Point is the physical characteristics of the bullet are primary in it's wounding effectiveness. As a rule of thumb more bullet = more wound, more reliably in more situations.

It appears you could be saying for instance, that a better bullet design in a smaller caliber is better than having a larger caliber with more energy. Is this what you mean?

xenophobe

03-15-2007, 12:35 PM

Bird rounds have questionable penetration capabilities. If some big guy is wearing a tough jacket and you have to shoot through his arm to get to his torso, is a bird load going to get through all that?

Umm... Yeah. Just the sheer amount of force transferred with a direct hit will give you enough time for a second or third shot. If a big guy with a tough jacket is hit, he'll go down. There is no such thing as Superman, ya know? lol

Overpenetration? Eh. There are so many walls and fences and other obstructions between my neighbors and I that I'd have to be tremendously unlucky to hit anyone accidentally. I don't judge that to be a major risk, compared to the risk that birdshot won't get the job done.

The birdshot will inflict much more damage.

Geoffkoop

03-15-2007, 12:38 PM

Me, with a 45-70 Govt.

True, the 45-70 is a crazy round! One of my favorites.

Aluisious

03-15-2007, 12:40 PM

It appears you could be saying for instance, that a better bullet design in a smaller caliber is better than having a larger caliber with more energy. Is this what you mean?

As a rule of thumb I'd say no. Of course the comparison has to be case by case.

A small high tech projectile can fail at expanding/fragmenting/whatever for numerous reasons, cover being an important one. A big ol' heavy bullet is going to stay heavy and big far more frequently, through cover, at different shot angles, etc. It's a more reliable mechanism.

Aluisious

03-15-2007, 12:42 PM

The birdshot will inflict much more damage.
Birdshot might destroy a greater volume of tissue, but a lot of it is going to be near the surface. I like 00 buck because it's going to go deep in a lot of situations and hit the major blood vessels or spine.

Birdshot won't do dink against anything protected by bone.

bwiese

03-15-2007, 1:16 PM

Projectile speed doesn't doesn't magically cause wounds by itself. 9 little .32 caliber holes have nine chances to hit "the good stuff" that ends a fight. A .223 with all it's speed doesn't mean dink if it doesn't hit a vital organ.

The hope is a .223 will fragment and destroy a large volume of tissue, but 00 buck will do the same without fragmentation anyway.

55gr M193 fragments around the cannelure and is more effective than the 62gr stuff.

Please read up some of the stuff on http://www.firearmstactical.com and/or ask lots of dead Viet Cong.

Jicko

03-15-2007, 1:17 PM

How about the 7.62X39mm? That is the round I'm most interested in. Also, in my scenario, it's most likely just the clothes that would be the obstruction and maybe some glass. If you had to pick between the AR15 or the AK47, which would it be and why?

AR15 w/ 77gr OTM or HPBT bullet... similar to Mk262.... it is loaded HOT, so even out of a 14.5" barrel, it is still coming out very fast.... and it is very accurate...

Caseless

03-15-2007, 1:25 PM

Back to the OP's queston. 5.56x45 vs. 7.62x39 'power-wise.'

I've shot 2x4 wooden blocks with both at close range. 7.62x39 knocks the blocks down. .223 does not.

From some online articles and interviews I've read, The Russian Spetsnaz usually prefer the AK-103 (modernized AK-47) when fighting close-quarters in Chechnya, as opposed to using AK-74 firing the 5.45x39 round.

The Russian internal security force has gone a step further and are now equipped with rifles firing 9x39 mm rounds.
Then again, they may need the bigger rifle rounds to stop the Siberian brown bears.;)

pepsi2451

03-15-2007, 1:56 PM

Coke or Pepsi?

Pepsi

Aluisious

03-15-2007, 2:00 PM

55gr M193 fragments around the cannelure and is more effective than the 62gr stuff.

Please read up some of the stuff on http://www.firearmstactical.com and/or ask lots of dead Viet Cong.

Please refer to my "case by case" caveat that I already posted.

You are so quick to argue you don't even bother to figure out what you're arguing against.

adamsreeftank

03-15-2007, 2:40 PM

...
The birdshot will inflict much more damage.

I used to think birdshot would be a good home defense load, but then we all heard about someone getting hit in the face with it and living without too much truama, so I wouldn't use it anymore.

Personally, in a 12 guage, I like slugs. I know they will penetrate like a mother, but hopefully a single well placed shot will be all that is required to stop an imminent threat.

In an AR type platform, the 6.5 grendle has LOTS going for it. It has more energy than an .223 at close range and more energy than a .308 at longer range. It's really a modern wonder bullet that can pretty much do it all.

Morales

03-15-2007, 5:25 PM

Well, it depends what you mean. If by stopping power you mean, "knock down" power, then there is no dispute that 7.62x39 is more effective. If you are talking about lethality, then 5.56 is more deadly. And let me explain, because I'm not a big fan of the 5.56. The Soviet M43 (7.62x39mm) was designed like most rounds of the age: to inflict grievous wounds. The thinking back then was that it was best to wound an enemy soldier because you took two men, maybe three out of action:

1. The wounded man
2. A man to pull him out of battle
3. A man to tend to him while the medic arrives.

On the other hand, the 5.56 is meant to inflict a fatal wound, which is fine for the enemy because they can leave the dead man on the field. This is of course assuming you hit the target in a vital area to begin with, as reports from Iraq indicate that the 5.56 is ineffective unless a torso, pelvis, or head shot is made. Any way, thats my contribution, I'm sure there are tons of guys who are going to say that what I just said is bunk.

ts

03-15-2007, 5:54 PM

At close range a 7.62x39 would be much more effective. IMO but it sounds to me like your looking for one of these weapons for self defense. possibly in your home, I would not recommend that since if you miss or it goes right through the target into your neighbors house killing their small child or what not. 7.62x39 was decided upon because they did not see the need for a long range round. Times have changed and 5.56 would be a better option for the US Military. If I was a LEO I would much rather have a 7.62x39 then an 5.56 - but I would be worried shooting it anywhere close to any people at all.

MrLogan

03-15-2007, 6:26 PM

Technically speaking, the 7.62x39 has more knock down power. But a 5.56, whether it be M193, M855, or MK262--while perhaps having less knock down power--, will KILL. It may not have as much stopping power, but it has KILLING power.

NwG

03-15-2007, 7:50 PM

IMO todays advanced rounds chambered in 5.56 give it the edge. It is pretty hard to find a "advanced" round for the AK (Tho the Mil. rounds arn't all that bad!) They are out there, or you can stuuf your own.. While I am almost always a firm preacher in the bigger hole is better club, is this case IMO the 5.56 wins..

The TAP round has showen to be very effective and it what I use for my HD AR.

That is when the shotgun is out of reach.. IMO 12g buckshot (4-00) is the most effective fight stopper for HD.. Not everyone will agree with me on that, but hey this is guns and we could fight to the end of time about this and that... It is hard to denie that 2500ft/lbs in a 2-3" package is not a good fight stopper.. Used correctly follow-up shots are very fast.. The only problem is limited capacity and slow reloading.. The latter can be vastly improved with proper training.. As to birdshot for bad guys... Blowing all the tissue off the rib cage may look nasty, but if it dosen't reach the pipes and pump its not worth shooting...

MrLogan

03-15-2007, 8:03 PM

IMO todays advanced rounds chambered in 5.56 give it the edge. It is pretty hard to find a "advanced" round for the AK (Tho the Mil. rounds arn't all that bad!) They are out there, or you can stuuf your own.. While I am almost always a firm preacher in the bigger hole is better club, is this case IMO the 5.56 wins..

The TAP round has showen to be very effective and it what I use for my HD AR.

That is when the shotgun is out of reach.. IMO 12g buckshot (4-00) is the most effective fight stopper for HD.. Not everyone will agree with me on that, but hey this is guns and we could fight to the end of time about this and that... It is hard to denie that 2500ft/lbs in a 2-3" package is not a good fight stopper.. Used correctly follow-up shots are very fast.. The only problem is limited capacity and slow reloading.. The latter can be vastly improved with proper training.. As to birdshot for bad guys... Blowing all the tissue off the rib cage may look nasty, but if it dosen't reach the pipes and pump its not worth shooting...

Yeah, birdshot is for small birds. Despite what some may say, birdshot is horrible for defense.

Adog5

03-15-2007, 8:30 PM

I'm the original poster and I appreciate all the input. I was trying to stay in discussion with exactly the two calibers and with the 14.5" AR15 barrel and normal 16" AK47 barrel. I understand that with a 16" AR15 barrel the fragmentation probability within 100 yards is very high, but again, we are dealing with a 14.5" barrel, therefore, would you pick the AK47 over that?

Lots of people thought it was a home-defense question, so the 'Shotgun' was brought up multiple times. People mentioned the 6.8 SPC, the 6.5 Grendel, all of which I've done research on. If I could choose the rifle and caliber for all around, it would be the 6.5 Grendel out of a Gas Piston AR15 with a 14.5" barrel. However, I LIVE IN CALIFORNIA and I can't get high cap mags for this dream rifle. I do have old AR15 and AK47 mags. I've looked into possible modifying them for the Grendel, but it's a no go (not going to go into it for this discussion).

Yes, this is free discussion, but I'm hoping to see if someone can explain to me which of the two choices would be ideal in a close combat range within 100 yards. If the ammo is important, then mention the ammo, which some people have done and I appreciate that (like the mk262). But they didn't mention to the get the mod 1 version. :D Anyway, the rifles are a set barrel length, so it's either the ammo type or something else that give each weapon their advantage in close combat.

Maybe I have to offer $100 to the best answer on this topic? Then maybe I'll get more response on exactly what I need? hahaha j/k I need it for the ammo.

MrLogan

03-15-2007, 8:39 PM

Within a CQB setting, with a 14.5" barrel, M193, M855, and MK262 will all fragement pretty reliably. It's when you get into longer ranges that you will have to use a heavier round (MK262) to get more reliable fragmentation.

In my experience, people who get hit with 5.56 die. End of story.

Bishop

03-15-2007, 8:41 PM

Whichever you can use to get three on the target the fastest! :D
I think, after that comes accuracy long range, then how much you can carry.

I'd rather carry more and be able to take accurate shots. If I was a newb, I'd want an AK. (not getting into AK vs AR debate, I still want an AK!)

pewpewguns

03-15-2007, 8:55 PM

Whichever you can use to get three on the target the fastest! :D
I think, after that comes accuracy long range, then how much you can carry.

I'd rather carry more and be able to take accurate shots. If I was a newb, I'd want an AK. (not getting into AK vs AR debate, I still want an AK!)

http://www.lakesideguns.com/title1/upper.html

Fits all the qualifications flawlessly :D

Vepr62

03-15-2007, 8:56 PM

back in the day I had a choice to carry ak-74 (5.45X39) close equivalent of 5.56. or ak-47, chambered in 7.62X39. All the people in my platoon prefered ak-47, except our machine gunner was using RPK-74. We didn't have any optic back then, and with ak-47 if you can ID your target, you can take it down with a short burst. For a machine gunner, he just preferd to carry more ammo.
Vasiliy

Dr. Peter Venkman

03-15-2007, 9:43 PM

Me, with a 45-70 Govt.

What? No .45-110?

I'd take the 7.62x39. I want to make a bigger entrance wound that will on top of that have greater knock down power than a varmint round.

E Pluribus Unum

03-15-2007, 10:48 PM

It is a matter of physics.... bullet weight....

Whats worse? getting hit with a ball pined hammer or a sledge hammer? If you aim for the right place it wont matter; if you aim center mass I would take ball pined any day.

adamsreeftank

03-16-2007, 1:06 AM

$100 you say. OK, I'll bite.

While you could research and do gelatin test until the cows come home, the bottom line is that within 100 yards, the rounds are prety comparable. With either round, a hit to a vital organ will likely be fatal, and a hit to non vital tissue or bone will wound but probably not be rapidly fatal within the context of a gunfight. IE, the potential for returned fire will exist.

With that in mind, other considerations should take precedence. Do you plan on using optics? The AR may be the better platform. Do you live in a dusty environment and want to avoid maintenance? Then the AK may be a better platform. If you have standard cap mags in both calibers then that is a non issue. You may not care about looks, but some people will make a purchase based on the appearance they prefer, all other things being equal.

Did I win?

E Pluribus Unum

03-16-2007, 1:14 AM

Did I win?

Nope.... I agree the rifles serve different purposes... a short barrel M4 would be better for CQB but at distances 50 meters+ the ballistics of the 30 caliber is better. Bad guys don't jump out with a sign that says "shoot me"; they hide behind things. 7.62 rounds penetrate better, plain and simple; they turn cover into concealment.

I would agree that in some instances the M4 is a better choice. The gap narrows as distance increases. Beyond 50 meters give me the M14.

Now... AK vs. AR.... that is a bit different because the AK is not as accurate out to extreme distances.

I think in a pinch I would rather have an AK over an AR; it would be a hard choice though.

Stanze

03-16-2007, 1:27 AM

Pretty interesting findings on http://www.theboxotruth.com

5.56mm M193: http://www.theboxotruth.com/docs/bot16_3.htm

7.62x39mm: http://www.theboxotruth.com/docs/bot16_5.htm

If I had to get shot by either one, I'd prefer the AK round due to less likelyhood of the bullet tumbling through my body, I'd hope the bullet missed vital organs and I'd be able to recover.

I like how faster precise follow-up shots are easier on the less recoiling 5.56mm round and more consistent accuracy of the 5.56mm round compared to the 7.62x39mm.

Well, it depends what you mean. If by stopping power you mean, "knock down" power, then there is no dispute that 7.62x39 is more effective. If you are talking about lethality, then 5.56 is more deadly. And let me explain, because I'm not a big fan of the 5.56. The Soviet M43 (7.62x39mm) was designed like most rounds of the age: to inflict grievous wounds. The thinking back then was that it was best to wound an enemy soldier because you took two men, maybe three out of action:

1. The wounded man
2. A man to pull him out of battle
3. A man to tend to him while the medic arrives.

On the other hand, the 5.56 is meant to inflict a fatal wound, which is fine for the enemy because they can leave the dead man on the field. This is of course assuming you hit the target in a vital area to begin with, as reports from Iraq indicate that the 5.56 is ineffective unless a torso, pelvis, or head shot is made. Any way, thats my contribution, I'm sure there are tons of guys who are going to say that what I just said is bunk.

WTF? Torso, head or pelvis? Whats left? An arm or a leg? A hit to an arm or a leg has a very low probability of being fatal with ANY caliber, unless of course it's a .50BMG and you blow his arm or leg completely off! :eek:

luvtolean

03-16-2007, 8:16 AM

It is a matter of physics.... bullet weight....

Whats worse? getting hit with a ball pined hammer or a sledge hammer? If you aim for the right place it wont matter; if you aim center mass I would take ball pined any day.

Physics says:

Force = 1/2 * mass * velocity squared.

Would you rather get hit by a Hummer at 20 MPH, or a motorcycle at 80?

Take the Hummer, trust me....

Neither of these rounds has any sort of thing such as "knock down power".

bwiese

03-16-2007, 8:47 AM

Luvtolean is correct.

There really is no such thing as 'knock-down power'. That's a perception, led by body-driven effects *after* being shot and after round has done damage.

A typical 230gr 45ACP bullet at ~750fps has ~280 ft-lbs of (muzzle) energy:
290ft-lbs is the energy required to move 290 lbs one foot.

In all these cases, since the energy is not 100% coupled to the body, some fraction of impact is lost to heat, much/most of it's lost to coupling energy to the tissues of the target body and their distortion, shearing, etc. Thus very little energy will be available to move the whole body backward. The idea a standard bullet hit has enough energy to move a body back is erroneous; the body may have its own responses (fight/flight/shock, etc.) but those are self-generated.

The efficiency of energy coupling to the target tissue determines wounding effects.

However, the real goal is to stop a threat. ANY bullet that does not stop CNS or cause blood depressurization/mass outflow - while possibly killing the guy just down the line - does not take him out of the fight game.

And there have been many many folks hit by ~147-150gr 308/30-60 (for mil loads these are essentially indistinguishable at close to mid ranges, and that are still alive to talk about it Bullet had fair speed, reasonable weight - but bullet just didn't cause large enough temporary wound cavity to open up and cause disruption to internal organs enough to kill the dude.

Oswald2001

03-16-2007, 9:05 AM

They are both lethal.

It is interesting to note that the Soviets decided to (basically) go the way of the 5.56 with their adoption of the 5.45 x 39.

Go for multiple hits.

Then it won't matter which caliber.

The effect of multiple hits is not directly proportional. Two hits generally do more than twice the damage to an adversary which is one of the 'benefits' of the 5.56. IF the 5.56 fragments, there are multiple wound channels with each wound channel having essentially the effect of a separate hit.

To me, each round has it's benefits and drawbacks. Just do your best to have more than one hit.

The old AK round did very well in Viet Nam in actual combat as did the 5.56. Same thing in Iraq and Afghanistan.

PIRATE14

03-16-2007, 9:08 AM

For some reason, I can't get any volunteers to help me out and see which one is better..............but you have to hit your tgt....that's the key to success;)

Technical Ted

03-16-2007, 9:39 AM

For some reason, I can't get any volunteers to help me out and see which one is better..............but you have to hit your tgt....that's the key to success;)
Wait....no matter what color or caliber it is or how much high tech gear like lasers, lights and sights you hang on your gun it won't be lethal unless you aim it properly and pull the trigger?

Each platform, and each round, excels or fails to excel depending on the variables in any given permutation.

At a longer distance, you've got a better chance of hitting the subject with the AR and a 5.56 round because of its inherently greater accuracy. So, even if you've got a better chance of a one hit takedown with the AK and a 7.62 round - the big IF there is whether you can get a hit on the subject at the longer distance, which is a lower probability with the AK and a 7.62 round, if everything else in the equation is equal.

At really close range, you're going to mess them up bad with a AK and a 7.62 round, and hitting the subject will be far less of an issue at short range.

Then you have to get into the whole question of whether "stopping power" means energy transfer or tissue damage to the subject. The 7.62 is going to put a good size hole in your subject, front and rear. The 5.56 is going to make a smaller hole and chew them up inside pretty badly. What's going to "stop" the subject sooner, and more fully? Well, hopefully you're not trying to take down Rasputin, who seemed to demonstrate a remarkable resiliency. The point is, that the answer is likely unknowble, and has a whole lot more do to with who you're shooting, what they're wearing, what tissue and organs you perforate with your shot, and what kind of constitution the subject possesses, than it does with the round you're using.

On the other hand, if you're talking about shooting someone who has intruded into your home, a load of 12 GA 00 will provide all the "stopping power" you need, and then some. You will then have to call a coroner, a house painter and a carpet layer to take care of what's left. You may want to call a realtor, too, since the on-demand video replay in your brain might be a bit much to handle on a daily basis.

I talk to a guy on an almost daily basis that was shot by police with 12 gauge "OO" Buck. It stopped him, but not dead. He spent 8 years in a wheel chair and still walks with difficulty. He was hit center mass. I saw the scars left over from the operations. One is down the center of his chest like he had open heart surgery. I realize this is a secluded case, but take nothing for granted. I don't know if what he went through would be considered "lucky" but all that "00" missed his vitals. He was shot point blank in the hallway of his home and was conscious enough to remember that one projectile had found its way to his rectum and he said the burning from the heat of it was something he won't forget.

I learned 2 things from his experience. A load of "00" may not always be the final solution, and to shoot twice.

Adog5

03-16-2007, 10:41 AM

It is interesting to note that the Soviets decided to (basically) go the way of the 5.56 with their adoption of the 5.45 x 39.

Go for multiple hits.

Hi again from the Original Poster. Here are my conclusions on what I've read from everyone. I was thinking more about Oswald's comment about the Russian adopting the 5.45X39, which made me wonder why didn't they just stay with the 5.56X45mm (NATO)? I know that the Russia don't just drop the popular 7.62X39mm round unless they know for sure there is an clear advantage with a new caliber. The only thing that makes sense to me is that they really understood the power of a fragmenting bullet in soft tissue. And I do know that test have been done on the 5.56 and they said that to reliably fragment it, it has to be over 2,700 ft/sec. By decreasing the bullet diameter, they were able to lengthen it, creating better ballistic coefficients, having the bullet travel 250 ft/sec faster out of the same barrel length of a 5.56, faster yaw upon entry of soft tissue, longer bullet give the tumble more surface area, therefore faster and more devasting fragmentation. Basically, their new bullet has a very high probablity of fragmenting in soft tissue even beyond 100 yards.

I was looking for more ammo available for the 7.62X39mm and there's not much out there except FMJ and a SP. I was hoping Hornady would have some TAP ammo for it, but there's none. However, the 5.56 as we know have developed some great ammo. On Hornady's site, they mention how they make their bullets easier to fragment...etc.

Another way that I was looking at it was that fragmentation is an analogy for exploding bullet. I know that technically it's not an "exploding bullet", but if you think about it, the AK47 round doesn't explode, but tumbles. The tumbling wound is only as big as the bullet length. However, when a bullet tumbles and then fragments, the fragmentation pieces actually causes greater tissue wound. To explain this, imagine an ice cube. Does that ice cube melt faster in your mouth, than if you crushed that ice cube into many pieces and then put it into your mouth? Why does it melt faster? Because there is more surface area around all the small pieces than if you added up the surface area on the ice cube. However, if the AK47 round also fragmented, then hands down it would be better that the 5.56 in close combat. If you don't believe me, just put a AK47 bullet next to a AR15 bullet and see the size difference and now imagine both of them fragmenting explosively in soft tissue.

Ok, so my conclusion is that due to the modern improvements on ammunition, the 5.56 is superior to the AK47 in close combat. If the 5.56 didn't fragment and just tumbled, the AK47 round does the same thing and has a larger surface area, therefore the AK47 round would win in that case. Even out of 14.5" barrel, with the 55gr TAP ammo, I'm confident it's better than the current AK47 ammo available. Also, I do agree multiple shots are good, therefore follow up shots with the AR15 are definitely easer than the AK47. Also, it's easier to mount accessories on the AR15, so I'm very happy with my conclusion.

I thank everyone for their input. I like the imagine of that guy holding both an AK47 and AR15, which reminded me of replacing the gernade launcher under the AR15 with a single shot 12 guage shotgun. Then I'd have a home defense gun eh? And yes, Pepsi is better than Coke. :D

Technical Ted

03-16-2007, 11:18 AM

Hi again from the Original Poster. Here are my conclusions on what I've read from everyone. I was thinking more about Oswald's comment about the Russian adopting the 5.45X39, which made me wonder why didn't they just stay with the 5.56X45mm (NATO)? I know that the Russia don't just drop the popular 7.62X39mm round unless they know for sure there is an clear advantage with a new caliber.
LOL. How old are you Adog?

Once upon a time, Russia was the country that lead a group of countries that was known as the USSR, or Soviet Union. The Soviet Union and the United States were opponents in something called The Cold War.

From a military strategic viewpoint, typically it's not a good idea to produce weapons that are compatible with your enemy's weapons. The Russians even incorporated this philosophy into their rail system: The Russian rail gauge is different from the rest of Europe to prevent an invading force from using their rail system against them.

The change to 5.45X39 began before the Cold War ended and the Soviet Union collapsed.

ETA: FWIW Terminal Ballistics, how a projectile performs in a body, wasn't a factor in the design of either the 5.56X45 or 7.62X39. The primary concern was with exterior ballistics, and in the case of the 5.56X45 round, whether it wouldn penetrate the old M1 steel helmet at 500 yds. Research in terminal ballistics wasn't a concern until an Army surgeon by the last name of Fackler began looking into the damage effects of projectiles. Today that research is being carried on by Dr, G K Roberts of the US Navy Reserve.

Teletiger7

03-16-2007, 11:20 AM

Why was he shot by police in the hallway of his own home!?????:eek:

I talk to a guy on an almost daily basis that was shot by police with 12 gauge "OO" Buck. It stopped him, but not dead. He spent 8 years in a wheel chair and still walks with difficulty. He was hit center mass. I saw the scars left over from the operations. One is down the center of his chest like he had open heart surgery. I realize this is a secluded case, but take nothing for granted. I don't know if what he went through would be considered "lucky" but all that "00" missed his vitals. He was shot point blank in the hallway of his home and was conscious enough to remember that one projectile had found its way to his rectum and he said the burning from the heat of it was something he won't forget.

I learned 2 things from his experience. A load of "00" may not always be the final solution, and to shoot twice.

force equals one half mass times acceleration squared
which really means.. whatever can penetrate your skill has the better stopping power :)

Teletiger7

03-16-2007, 11:29 AM

7.62 X39mm barrier penetration video

http://www.youtube.com/watch?v=_0UdI1No82A

xenophobe

03-16-2007, 11:30 AM

I used to think birdshot would be a good home defense load, but then we all heard about someone getting hit in the face with it and living without too much truama, so I wouldn't use it anymore.

Personally, in a 12 guage, I like slugs. I know they will penetrate like a mother, but hopefully a single well placed shot will be all that is required to stop an imminent threat.

At close range it is absolutely deadly. At farther ranges, it won't cause much damage. That is the whole point of using a low base birding round. You don't want someone receiving indirect fire 30' away getting critically hurt. Standard velocity 00 buck and slugs are much more deadly at farther distances. Then again, I'm talking about self defense in an urban area where excessive penetration and long range lethality aren't needed, and generally not wanted and any 'encounters' would most likely be less than 7y.

In my home in Mtn View, if I shoot 00 buck or a slug and miss, it WILL go into my neighbors house. That is a risk I would never be willing to take.

In an AR type platform, the 6.5 grendle has LOTS going for it. It has more energy than an .223 at close range and more energy than a .308 at longer range. It's really a modern wonder bullet that can pretty much do it all.

But the drawback is you need a relatively long barrel 20-24' to realize the potential. A 6.8 SPC only needs 14.5' to realize it's effective potential. 6.5 Grendel is not a CQB round, but 6.8 SPC is relatively accurate to 400-500y, although it's best under <300.

Technical Ted

03-16-2007, 11:31 AM

Wrong, atomic powered robots with frickin' laser eyes kill people.

:D
Damn straight ;)

paradox

03-16-2007, 11:45 AM

At close range it is absolutely deadly. At farther ranges, it won't cause much damage. That is the whole point of using a low base birding round.

In order to kill a raccoon at three yards, I need to use high base duck or turkey loads: low base birdshot just makes them squeal and run away.

I personally wouldn't want to protect my life and the lives of my family with something that can't kill a 'coon.

Paratus et Vigilans

03-16-2007, 12:21 PM

From a military strategic viewpoint, typically it's not a good idea to produce weapons that are compatible with your enemy's weapons. The Russians even incorporated this philosophy into their rail system: The Russian rail gauge is different from the rest of Europe to prevent an invading force from using their rail system against them.

My first thought, too!

You beat me to it, TT!

The Russians have a real thing about having their own stuff turned against them. They also were adamant about having a buffer zone between them and the West when they were the USSR, which is why they took and kept their "satellite" neighbors during the Cold War. Between Napoleon and Hitler, they got sick of having the Rodina overrun by their enemies. And they have nothing but enemies and client states - they have no friends at all. Makes it pretty lonely out there for them, but they don't have anyone they trust the way we trust, say, the Brits. Say what you will about the Brits, but if the SHTF, they'll stand with us, as we do with them. Can you think of a single ally that would do that for the Bear? Nyet.

Adog5

03-16-2007, 12:47 PM

LOL. How old are you Adog?

Once upon a time, Russia was the country that lead a group of countries that was known as the USSR, or Soviet Union. The Soviet Union and the United States were opponents in something called The Cold War.

From a military strategic viewpoint, typically it's not a good idea to produce weapons that are compatible with your enemy's weapons. The Russians even incorporated this philosophy into their rail system: The Russian rail gauge is different from the rest of Europe to prevent an invading force from using their rail system against them.

The change to 5.45X39 began before the Cold War ended and the Soviet Union collapsed.

ETA: FWIW Terminal Ballistics, how a projectile performs in a body, wasn't a factor in the design of either the 5.56X45 or 7.62X39. The primary concern was with exterior ballistics, and in the case of the 5.56X45 round, whether it wouldn penetrate the old M1 steel helmet at 500 yds. Research in terminal ballistics wasn't a concern until an Army surgeon by the last name of Fackler began looking into the damage effects of projectiles. Today that research is being carried on by Dr, G K Roberts of the US Navy Reserve.

I do agree that they didn't know about fragmentation when they developed the 5.45 and that they did it to be able to penetrate a helmet at a certain distance. But why did they step so far down from the 7.62 which was a proven effect round? The 6.5 Grendel actually performs better and has better armor piercing range than the 5.56 and 5.45. So shouldn't the Russian have developed a cartridge around here? I guess then it has to be the weight and having more ammo that caused them to go below 5.56.

http://www.answers.com/topic/assaultriflecartridgecomparisonchart-png

Also, since I'm so young, could you point me to information on why it's a bad idea to have weapons that are compatible with your enemy? If I'm invading another country, I would want the same ammunition, so my front line soldiers wouldn't have to worry about being resupplied. It works both ways. There are pro and con's. But if my weapons are superior to the enemy, and fires the same caliber, (for example my guns have laser pointer or a better scope), then I'm expecting I'll drop more enemies and be able to push forward by using their ammo and not having to worry about ammo resupply. Also, even if the weapons are not compatible, if the enemy is dead so that I could pick up his ammo, couldn't I also pick up his weapon? Does compatiblity matter at that point? I'm wondering if you can explain logically why it's better to not have weapons that are compatitible with your enemy? Are you just following some famous general's strategy, or do you have logic behind it?

Actually, during the Cold War, they were supplying other countries that supported Communism. But supplying that country with ammo would be additional cost and logistics in a war. Wouldn't it be easier to use the enemy's ammo, so that you only have to give your comrades enough ammo to kill the enemy and steal theirs? Espeically, if you are trying to expand communism?

Paratus et Vigilans

03-16-2007, 12:58 PM

Incorporating the capture and use of enemy ammo and weapons as part of your battle plan is not terribly prudent. You need to KNOW what weapons and ammo you can count on having with you as you drive into enemy territory, and so you count on BYO.

When you have to unexpectedly bug out of a position, you may not have time to destroy those of your weapons and ammo you can't take with you. So, you don't want to arm your enemy.

An enemy soldier will not hesitate to pick up spare USABLE ammo for HIS weapon from an enemy KIA on the battlefeld, but he's not usually going to dump his own issue weapon and take the enemy KIA's weapon instead, and he's not going to hump around TWO weapons, his issue and the enemy KIA's, and he's sure not going to abandon his issue weapon in favor of the enemy KIA's weapon, when his source of ammo for it in the future is uncertain at best.

That's why.

Also, FWIW, look what happened to the schools when they started planning on lottery money as part of their regular budget instead of treating it as an unreliable bonus. Same concept, same bad result.

When it comes to guns and ammo, like drink, if you don't want to be disappointed, BYO! :D

Technical Ted

03-16-2007, 1:05 PM

Also, since I'm so young, could you point me to information on why it's a bad idea to have weapons that are compatible with your enemy? If I'm invading another country, I would want the same ammunition, so my front line soldiers wouldn't have to worry about being resupplied. It works both ways. There are pro and con's. But if my weapons are superior to the enemy, and fires the same caliber, (for example my guns have laser pointer or a better scope), then I'm expecting I'll drop more enemies and be able to push forward by using their ammo and not having to worry about ammo resupply.
Ammo is easy to sabotage. Never trust captured munitions until you have time to evaluate it. You ever wonder why the US military destroyed so many of Saddam's ammo and munitions dumps after the invasion?

bwiese

03-16-2007, 1:22 PM

Ammo is easy to sabotage. Never trust captured munitions until you have time to evaluate it. You ever wonder why the US military destroyed so many of Saddam's ammo and munitions dumps after the invasion?

We actually sabotaged 7.62x39 and 7.62x54 ammo in Vietnam in 60s.

Every coupla thousand rounds one of 'em would be charged with some C4.

pewpewguns

03-16-2007, 1:53 PM

We actually sabotaged 7.62x39 and 7.62x54 ammo in Vietnam in 60s.

Every coupla thousand rounds one of 'em would be charged with some C4.

That is sooooo cool.

How would the C4 detonate? I wouldn't think a primer would set it off.

Technical Ted

03-16-2007, 2:11 PM

How would the C4 detonate? I wouldn't think a primer would set it off.
What do you think a blasting cap is? It's simply an ignition primer.

pewpewguns

03-16-2007, 2:36 PM

What do you think a blasting cap is? It's simply an ignition primer.

I don't know why, But I always though plastic explosives needed to be detonated with an electronic device.

You always see 'em shoving two prods of an electronic detonator into the C4 in the movies :p

http://en.wikipedia.org/wiki/Image:Eod2.jpg (http://en.wikipedia.org/wiki/Image:Eod2.jpg)Yes, they are filled with a primary explosive. Primary explosives are more sensitive than secondary, stable ones like C4 or dynamite.

The explosive compound in most bullet primers is lead styphnate, which is also a primary explosive.

Q

03-16-2007, 4:03 PM

interesting question on more effective tissue damage at 50yrds.
i think 762 since slower,heavier,and larger diameter bullet is more effective.
longer distances i would say 223 with it's fragmentation and high velocity.
here is a video about the OLDER m16 and ak47. http://www.youtube.com/watch?v=G6BpI3xD6h0&mode=related&search=
it has a cinderblock and wood test.

Oswald2001

03-16-2007, 4:46 PM

I am just going by recollection here.

I believe that the Russians saw the effects of the 5.56 in Viet Nam and wanted to get into a smaller caliber, lighter projectile, flater shooting round.

The 5.56 (close up anyway) relies on projectile fragmentation first and projectile tumbling second. The incredible damage that a fragementing round can do is largely lost if the round drops too much velocity when it is further down range.

The 5.45 relies primarily on the wounding resulting from a tumbling projectile. The 5.45 projectile is long and the weight is intentionally shifted toward the rear (with military rounds having an air space at the tip of the projectile). This results in almost immediate tumbling of the projectile as it enters a body mass at high or low speed.

Fragmentation diminishes as the velocity drops whereas tumbling is relatively independent of velocity drops within the velocity ranges involved in combat.

Fragmentation vs. Tumbling

Two approaches to the same 'problem'.

Aluisious

03-16-2007, 4:59 PM

At close range it is absolutely deadly. At farther ranges, it won't cause much damage. That is the whole point of using a low base birding round. You don't want someone receiving indirect fire 30' away getting critically hurt. Standard velocity 00 buck and slugs are much more deadly at farther distances. Then again, I'm talking about self defense in an urban area where excessive penetration and long range lethality aren't needed, and generally not wanted and any 'encounters' would most likely be less than 7y.

In my home in Mtn View, if I shoot 00 buck or a slug and miss, it WILL go into my neighbors house. That is a risk I would never be willing to take.

But the drawback is you need a relatively long barrel 20-24' to realize the potential. A 6.8 SPC only needs 14.5' to realize it's effective potential. 6.5 Grendel is not a CQB round, but 6.8 SPC is relatively accurate to 400-500y, although it's best under <300.

In all these cases, since the energy is not 100% coupled to the body, some fraction of impact is lost to heat, much/most of it's lost to coupling energy to the tissues of the target body and their distortion, shearing, etc. Thus very little energy will be available to move the whole body backward. The idea a standard bullet hit has enough energy to move a body back is erroneous; the body may have its own responses (fight/flight/shock, etc.) but those are self-generated.

The efficiency of energy coupling to the target tissue determines wounding effects.

However, the real goal is to stop a threat. ANY bullet that does not stop CNS or cause blood depressurization/mass outflow - while possibly killing the guy just down the line - does not take him out of the fight game.

And there have been many many folks hit by ~147-150gr 308/30-60 (for mil loads these are essentially indistinguishable at close to mid ranges, and that are still alive to talk about it Bullet had fair speed, reasonable weight - but bullet just didn't cause large enough temporary wound cavity to open up and cause disruption to internal organs enough to kill the dude.

To sum up for Bill:

There is no such thing as conservation of kinetic energy. There is only conservation of momentum.

"Knock down power" doesn't exist in any personal firearms, save for their capacity to inflict rapidly fatal wounds.

mike100

03-16-2007, 5:04 PM

One justification of the 223 caliber and russian equivalent is strategic/logistical in nature. you can carry a 1/3 more munitions for the same amount of overall weight. either on an individual soldier or in the back of a supply truck.

Once permanently stationed, I have read stories about russian soldiers re-equipping with 7.62x39 for fighting against chechen rebels and such in limited engagements where all they care about is knock down power at across the street distances for strictly urban use.

Aluisious

03-16-2007, 5:09 PM

Physics says:

Force = 1/2 * mass * velocity squared.

Would you rather get hit by a Hummer at 20 MPH, or a motorcycle at 80?

Take the Hummer, trust me....

Neither of these rounds has any sort of thing such as "knock down power".

No...you're thinking of kinetic energy.

Force is different. It's mass times acceleration. IE the force a bullet imparts on the target is a function of the bullet mass, the bullet velocity, and how quickly the bullet stops in the target.

If you have two .45 ACP 230gr bullets at 850 fps, one being an FMJ and one being a JHP, the JHP will exert more force on the target (stops faster), even though both have identical energy.

mblat

03-16-2007, 5:24 PM

From a military strategic viewpoint, typically it's not a good idea to produce weapons that are compatible with your enemy's weapons. The Russians even incorporated this philosophy into their rail system: The Russian rail gauge is different from the rest of Europe to prevent an invading force from using their rail system against them.

When first Russian rail road were designed ( in 1830s) the reason given for different track was purely economic. Wider track allowed for heavier trains and that especially beneficial for Russia due to the sheer land mass and therefore difficulties with saturating that space with enough trains.
I doubt very much that czarist Russia, fresh after conquering almost entire Europe and, as a result, being by the most influential country in the World at the time (with England close second) was worried too much about possibility of invading enemy using Russian reailroads.

luvtolean

03-16-2007, 5:59 PM

No...you're thinking of kinetic energy.

Force is different. It's mass times acceleration. IE the force a bullet imparts on the target is a function of the bullet mass, the bullet velocity, and how quickly the bullet stops in the target.

As I posted, if you apply a bit of calculus to MA, specifically, the change in velocity with respect to time you get 1/2 M*V^2. The second derivative would get you change in position over time...

If you have two .45 ACP 230gr bullets at 850 fps, one being an FMJ and one being a JHP, the JHP will exert more force on the target (stops faster), even though both have identical energy.

Not, necessarily true, but could be. The only way a bullet doesn't exert all of it's energy into the body is if it passes completely through. If the bullet goes all the way through, the remaining energy will go into what it impacts beyond the body.

If the body fully stops both bullets, they both exert the same amount of force on the body, it doesn't matter what construction they are. Or for that matter, what caliber. It's the same amount of energy. They may have travled more or less through the body. They may have left a different wound track. Some of the energy might go into fracturing a bullet at the cannulure...

An expanded JHP may stay in the same body hardball exits due to the larger frontal area of the bullet dissipating more energy per inch of body traveled. But that would be the only way a JHP transferred more of its energy to the body.

luvtolean

03-16-2007, 6:03 PM

When first Russian rail road were designed ( in 1830s) the reason given for different track was purely economic. Wider track allowed for heavier trains and that especially beneficial for Russia due to the sheer land mass and therefore difficulties with saturating that space with enough trains.
I doubt very much that czarist Russia, fresh after conquering almost entire Europe and, as a result, being by the most influential country in the World at the time (with England close second) was worried too much about possibility of invading enemy using Russian reailroads.

Dude, Napoleon was encamped in Moscow a decade before, and last time I checked, he wasn't Russian.

mblat

03-19-2007, 9:13 PM

Dude, Napoleon was encamped in Moscow a decade before, and last time I checked, he wasn't Russian.

Yes..... And how did it end for him?

mark3lb

03-19-2007, 11:48 PM

I saw a video about this and the ak did more damage. You might want to look online for it. ak vs ar. Cool.

Paratus et Vigilans

03-20-2007, 7:29 AM

Yes..... And how did it end for him?

Badly, of course, but the wide gauge rails in the USSR were in fact a military issue.

From Wikipedia:

Break of gauge has also been used deliberately for military purposes - for example, the Soviet Union had a different gauge from adjoining European countries to slow down invaders seeking to use its rail lines to move troops.

Link to entire article: http://en.wikipedia.org/wiki/Standard_gauge

Delta V

03-20-2007, 8:52 AM

Luvtolean is correct.

There really is no such thing as 'knock-down power'. That's a perception, led by body-driven effects *after* being shot and after round has done damage.

A typical 230gr 45ACP bullet at ~750fps has ~280 ft-lbs of (muzzle) energy:
290ft-lbs is the energy required to move 290 lbs one foot.

In all these cases, since the energy is not 100% coupled to the body, some fraction of impact is lost to heat, much/most of it's lost to coupling energy to the tissues of the target body and their distortion, shearing, etc. Thus very little energy will be available to move the whole body backward. The idea a standard bullet hit has enough energy to move a body back is erroneous; the body may have its own responses (fight/flight/shock, etc.) but those are self-generated.

This was nicely summed up by Sir Isaac Newton in 1687 in one of his seminal works Philosophiae Naturalis Principia Mathematica:

For those whose high schools neglected to offer Latin, "All forces occur in pairs, and these two forces are equal in magnitude and opposite in direction", more commonly paraphrased as "For every action force there is an equal, but opposite, reaction force".

In other words, if a bullet possessed enough action force to knock someone down, it's reaction force (commonly paraphrased as 'recoil') would do the same to the shooter.

mblat

03-20-2007, 4:44 PM

Badly, of course, but the wide gauge rails in the USSR were in fact a military issue.

From Wikipedia:

Break of gauge has also been used deliberately for military purposes - for example, the Soviet Union had a different gauge from adjoining European countries to slow down invaders seeking to use its rail lines to move troops.

Link to entire article: http://en.wikipedia.org/wiki/Standard_gauge

You HAVE to ask yourself a question. For obvious reasons the railways in Soviet Union were build exactly to the same specifications as railways in czarists Russia. Even communists were not about to replace thousands upon thousands miles of railroads just to change a gauge. So break in gauge existed for decades before anybody even heard world communism....
So this is nothing else, but a factoid. Just because it found itself a home in wikipedia, it still doens't mean it is true....